Emergency Zebra Mussels Order Signed

AUSTIN – Texas Parks and Wildlife Department Executive Director Carter Smith has signed an emergency order adding Lake Ray Roberts and Lake Lewisville to the list of water bodies under special regulations intended to control the spread of zebra mussels.

Smith’s action comes following the discovery in mid-July that the destructive invasive species had been found in Lake Ray Roberts, north of Denton.

The Texas Parks and Wildlife Commission earlier this year amended TPWD’s regulations to require that boats operated on Lake Texoma and Lake Lavon be drained (including live wells and bilges) before they leave those water bodies. Taking this precaution is crucial in efforts to slow the spread of this species, since contaminated boats are one of the primary ways this happens. Draining water from boats prevents the spread of a microscopic form of the zebra mussel called a veliger, which is invisible to the naked eye.

The emergency rule does allow a person to travel on a public roadway via the most direct route to another access point located on the same body of water without draining water from their boat. The emergency action would extend the applicability of the current regulation to all impounded and tributary waters of the Elm Fork of the Trinity River above the Lake Lewisville dam including Lakes Ray Roberts and Lewisville.

The zebra mussel is a small, non-native mussel originally found in Eurasia. It has spread throughout Europe, where it is considered to be a major environmental and industrial menace. The animal appeared in North America in the late 1980s and within 10 years had colonized in all five Great Lakes and the Mississippi, Tennessee, Hudson, and Ohio river basins. Since then, they have spread to additional lakes and river systems, including in North Texas.

Zebra mussels live and feed in many different aquatic habitats, breed prolifically, and cannot be controlled by natural predators. Adult zebra mussels colonize all types of living and non-living surfaces including boats, water-intake pipes, buoys, docks, piers, plants, and slow moving animals such as native clams, crayfish, and turtles. The U.S. Fish and Wildlife Service estimates the potential economic impact of zebra mussels to be in the billions of dollars.

Under authority granted by the Legislature, emergency rules can be adopted if the commission or the executive director finds that there is an immediate danger to a species authorized to be regulated by the department. This emergency rule will continue for no more than 120 days from the date this notice is filed with the Texas Register. TPWD will be preparing a non-emergency rule for consideration by the commission that would go into effect when the emergency rule expires.